Bug 14547: Typo in help file for 3.20 (basket.tt)

Bug 14547: Typo in help file for 3.20 (basket.tt)

Typo found in basket.tt file for Koha help in 3.20

Test plan:
1) Go to url 'koha-tmpl/intranet-tmpl/prog/en/modules/help/acqui/basket.tt:24' and check the typo "susbscription" or go to Acqusitions > create or view an existing basket, open up the help
2) Apply the patch
3) Repeat step 1 and check if the typo is fixed.

Sponsored-by: Universidad de El Salvador
Signed-off-by: Aleisha <aleishaamohia@hotmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>